IRS manual detailed DEA's use of hidden intel evidence (Reuters)(Reuters) - Details of a U.S. Drug Enforcement Administration program that feeds tips to federal agents and then instructs them to alter the investigative trail were published in a manual used by agents of the Internal Revenue Service for two years.

The practice of recreating the investigative trail, highly criticized by former prosecutors and defence lawyers after Reuters reported it this week, is now under review by the Justice Department. Two high-profile Republicans have also raised questions about the procedure.